Variable cut-off for steam-engines.



3 SHEETS-SHEET l No. 738,147. PATENTED SEPT. 8., 190.3. W. H. BATES (inR. C. DOUGLASS. VARIABLE GUT-OFF FOR STEAM ENGINES.

APPLICATION rum) SEPT. 25, 19021 no MODEL.

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No. 738,147. PATENTED SEPT. s, 1903. W. H. BATES & m0. DOUGLASS.

VARIABLE CUT-OFF FOR STEAM ENGINES.

I APPLICATION r Lnn SEPT. 25, 1902. no Monn L. s SHEETS-SHEET 2.

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KQ. 7382,1471 YATENTED SEPT. 8, 1903. W. IL; BATES 6: R. G. DOUGLA'SS.

VARIABLE GUT-OFF FOR STEAM ENGINES.

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UNITED STATES Patented September 8, 1903.

PATENT OFFICE.

WILLIAM H. BATES AND ROBERT C. DOUCLASS, OF CHICAGO, ILLINOIS, ASSIGNORSTO THE MARINE IRON WORKS, OF CHICAGO, ILLINOIS, A

CORPORATION OF ILLINOIS.

VARIABLE CUT-OFF FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No, 738,147, datedSeptember 8, 1903.

Application filed September 25, 1902. Serial No. 124,725. (No model.)

To (tZZ whom it may concern:

Be it known that we, WILLIAM H. BATES and ROBERT C. DOUGLASS, bothcitizens of the United States of America, residing at Chicago, in thecounty of Cook and State of Illinois, have jointly invented certain newand useful Improvements in Variable Cut-Offs for Steam-Engines, of whichthe following is a description.

Our invention belongs to that class of devices in which a supplementalsteam and valve chest is provided for controlling the admission of thesteam to the main steam-chest.

It has for its object the construction of suitable mechanism forcontrolling the length, position, or lead of the supplemental valve andsimultaneously therewith to control the length of the throw or travel ofthe same.

To this end our invention consists in the novel construction,arrangement, and combination of parts herein shown and described, andmore particularly pointed out in the claims.

In the drawings, wherein like reference characters indicate like orcorresponding parts, Figure l is a side elevation of a hori zontalmarine engine equipped with our invention. Fig. 2 is a top plan of thesame in partial section to show the arrangement. Fig. 3 is a detail Viewof the controlling mechanism for the supplemental valve, taken in theline 3 3 of Fig. 5. Fig. 4 is a similar view showing the parts in adifferent position, and Fig. 5 is a top plan of the same.

In the drawings, 1 represents the main steam-chest for the cylinder 2,provided with any preferred form of valve mechanism. As shown, thevalves 3 3 are connected by the stem 4 and operated by its engagementwith the rocker-arm 5 in the usual manner. Beside the main valve-chestis arranged a supplemental valve chest of any well known type. As shown,the cylinders 6 6 are provided with piston-valves 7 7, each mounted upona part of the valve rod 8, which is formed in two parts. By thusdividing the valve 8 the length, position, or lead of the valve may beregulated as desired. The object of the supplemental valve-chest and itsmechanism is to regulate the admission of steam to the main valve chest,or, in other words, to regulate the cut-off. By our device this can beefiectually accomplished Without throttling or wire-drawing the steam orin any way narrowing the steam-ports during the period of admissionthereto.

As shown in the drawings, 9 is a plate or equivalent lover or part,preferably circular in form and so supported in any convenient manner asto oscillate or freely revolve upon its center 10. The plate or the disk9 is actuated by an eccentric-rod 11 or equivalent means to impart aswinging or oscillating movement thereto, said movement being regulatedin relation to the stroke of the engine. As shown, the eccentric-rod 11is pivotally secured to the pin 12, positioned in the disk 9. In thepreferred form the disk 9 is provided with a set of guides 13 13,arranged to receive a small cross-head 14, so arranged that thecross-head may by any convenient means be shifted radically toward andfrom the center or fulcrum of the disk. The crosshead 14 is providedwith two lovers 15 15, pivotally connected thereto and secured to therod 8 Sin such a manner that the levers 15 15 and their connections willform a toggle-lever device, as shown in Fig. 3. Upon moving thecrosshead 14 outward the action of the toggle-lever will serve toseparate or part the rods 8 8 and the valve, and thus vary the positionor lead of the valves, as shown in Fig. 4:.

16 is a sleeve within which the free ends of the rods 8 8 are insertedand which serves to retain them in alinernent with one another.

It will be readily seen that the throw or travel of the supplementalvalve will also be regulated by the position of the cross-head 14 withinthe guides 13 13-that is to say, by the distance of said cross-head fromthe center or fulcrum 10 of the supporting disk or lever. Thus as, thecross-head is moved outward from the center the toggle connection willsimultaneously cause the stems S 8 to be separated, and thus lengthenthe valve, the single operation accomplishing both results.

Any suitable means may .be employed for controlling the adjustment ofthe cross-head 14 within the guides 13, as set forth. As shown in thedrawings, a lever 17 is pivotally supported between its ends, as at 18,Figs. 1, 3, and 4, having one end extended to and connected with thecross-head 14 and the other end engaged with a bar or lever 19, to whichit is pivotally connected. The bar 19 is connected with a bell-cranklever 20, pivotally supported, as at 21, and having one end 22 extendedto serve as a hand-lever to operate the same. A semicircular ratchet 23may be provided, with which the latch 24,

carried by the arm 22, operates to firmly hold and retain the parts inany desired position. By mounting the lever 17 on an oscillating arm 26,pivotally supported on the frame or other suitable part, the necessaryoscillation of the disk 9 is permitted. By thus simultaneously adjustingthe position or lead of the valve and its travel the steam may be cutoff at any desired part of the stroke from zero to the full strokewithout narrowing the steam-ports during admission.

Fig. 2 clearly shows the operation of our improvement and the cifect ofadjusting the supplemental valve, as described. The admission of steamto the ports 25 25 is regulated and controlled by said valve, while theadmission of steam to the cylinder of the engine is controlled by theoperation of the valves 3 3 in the usual manner.

Our invention is particularly applicable to horizontal marine engines,as shown, but may i be readily adapted to other forms of engines. Hencewe do not wish to be understood as limiting its use to marine enginesonly.

It is obvious that after having thus described ourv improvement variousmodifications may be made without departing from the spirit of ourinvention. Hence we do not wish to be understood as limiting ourselvesto the exact form and construction shown. It is also obvious that ourimprovement may be employed upon single-acting engines, if desired, inwhich case one end only will be necessary.

By the term lead in the claims we wish to be understood as meaning theposition of the supplemental valve when one only is employed in additionto the throw or travel of the same, and when two supplemental valves areemployed that the distance between them is varied.

Having thus described our invention, what we claim as new, and desire tosecure by Letters Patent, is

1. A variable cut-off device for steam-engines, comprising a mainsteam-chest and its valve, in combination with a supplementalsteam-chest and its valve, arranged to control the delivery of steam tothe main steamchest, and means for simultaneously adj usting both theposition or lead and the travel of said latter valve, substantially asdescribed.

2. A variable cut-0E device for steam-engines, comprising a mainsteam-chest and its valve, in combination with a supplementalsteam-chest and its valve, arranged to control the delivery of steam tothe main steamchest, said latter valve being formed in two parts, andmeans for simultaneously adjusting the parts to adjust the position orlead of the valve, and for regulating its travel, substantially asdescribed.

3. In a device of the kind described, a main steam chest and its valve,in combination with a supplemental steam-chest provided with a two-partvalve, adapted to be separated to regulate the position or lead of thesame, an oscillating part, a cross head'arranged upon said oscillatingpart adapted to be moved backward or forward with relation to the centerof oscillation, and a toggle-lever extending from said cross-head toeach of the parts of the valve, whereby upon shifting the position ofthe cross-head both the position or lead and the travel of the valvewill be regulated, substantially as described.

4. In a device of the kind described, the main steam-chest and itsvalve, in combination with a supplemental steam-chest provided with avalve composed of two parts and arranged to control the delivery ofsteam to the main chest, an oscillating part, a crosshead adj ustablysupported upon the oscillating part adapted to be moved backward andforward relative to the center of oscillation, toggle-levers connectingthe cross-head with each of the parts of the supplemental valve, and ahand-lever arranged to adjust the position of the cross-head upon theoscillating part, whereby both the position or lead and the travel ofthe supplemental valve may be controlled, substantially as described.

5. In a device of the kind described, the main steam-chest and itsvalve, in combination with a supplemental steam-chest provided with avalve parted at its middle, an oscillating part, guides 13 13, arrangedupon the oscillating part, a cross-head 14, engaging the guides,toggle-levers 15 15, connecting said cross-head with the two parts ofthe valve, and means for adjusting the position of the cross-head 14,relative to the center of oscillation, whereby the position or lead andtravel of the supplemental valve may be simultaneously adjusted,substantially as described.

6. In a device of the kind described, the main steam-chest and itsvalve, in combina= tion with a supplemental steam chest provided with avalve parted in the middle, an oscillating part, provided with guides 1313, a cross-head 14, arranged in said guides, toggle-levers 15 15,connecting said cross-head steamto the main steam-chestcontrolled,subwith the parts of the valve, a pivotally-supstantially asdescribed.

ported arm 26 earryin a lever 17 havin one end engaged With an?cross-head, and the other end extended and engaged with a hand- I lever,whereby both the position or lead and Witnesses: the travel of thesupplemental valve may be W. G. NO URSE, simultaneously adjusted, andthe cut-off of JOHN G. KREER.

